The field of invention involves underwater vehicles (UVs). The field of UVs includes autonomous underwater vehicles (AUVs), remotely operated vehicles (ROVs), and supporting mobile and stationary tools, stations, and equipment.
Over two-thirds of our world is yet to be explored and this portion of our world is underwater. Even though almost every surface inch of this domain may be accessible, adventures and discoveries to the underwater environment have lagged behind our adventures into space. One of the major hurdles to exploring and operating underwater is the lack of sufficient electricity for the autonomous underwater vehicles (AUV""s), remotely operated vehicles (ROV""s) and stationary underwater structures.
Electricity has been supplied to remotely operated vehicles and stationary underwater structures through tethers, whose length limits the depth at which a remotely operated vehicle or stationary underwater structure can operate. Further, tethers are cumbersome and can become tangled when more than one remotely operated vehicle is employed. Also, the tether and associated support systems often equal the cost of the remotely operated vehicle. In addition, the ROV and stationary underwater structure can be employed no longer than the surface vessel upon which it relies for electricity. This limits the time that the remotely operated vehicles and stationary underwater structures can be operated. Untethered vehicles, such as autonomous underwater vehicles, are time limited as well based on their ability to generate and store electricity.
Presently, there exists an unmet demand for autonomous underwater vehicles that are capable of operating underwater for extended periods of time independent of physical human intervention. One problem with present autonomous underwater vehicles is their dependence on batteries as the source of their electricity. The use of batteries limits the functional capabilities of the autonomous underwater vehicles by requiring the autonomous underwater vehicle to resurface constantly to exchange or recharge depleted batteries. The power systems employed by today""s autonomous underwater vehicles are capable of operating 72 hours or less, before their electrical energy supply is depleted and they are brought back to the surface for recharging or replacement of batteries, which process is time consuming. This significantly limits the usefulness of today""s autonomous underwater vehicles, especially in light of the demand for autonomous underwater vehicles to be operational for months at a time.
Stationary underwater structures, which generally receive their electricity from turbines or tethers, are afflicted by the same problem. The use of underwater turbine power generators for generating electricity from water current flow, such as rivers and oceans, is known in the art. Turbines have been used to produce electricity underwater. There are two common types of turbine devices: stationary turbines and tethered turbines. Stationary turbines are comprised of stationary towers based on the ocean floor. Electricity generating turbines are mounted on the towers at a fixed depth, with turbine rotor blades facing the flow of an ocean current. Tethered devices are designed to operate underwater, and are kept in place by a tether that is anchored to the ocean floor. The electricity generated by these turbine configurations is commonly stored in an array of batteries. Both the stationary and tethered turbines depend on underwater currents to drive the large turbine rotor blades. This limits the possible configurations of vehicle types or platforms that can employ this type of electricity generation. Large underwater turbines are not useful with mobile underwater vehicles such as autonomous underwater vehicles and remotely operated vehicles. Due to the vast array of onboard devices and apparatuses, these vehicles have dynamic electrical power demands and must be capable of maneuvering in tight areas that preclude the use of tethers and bulky turbines.
Electricity for use in underwater systems can also be generated from the use of internal combustion engine generators aboard a surface vessel. The surface vessel then supplies power to a stationary underwater structure or remotely operated vehicles via a tether. These internal combustion engine generators use hydrocarbons as fuel to power the generator. Handling and storing of this hydrocarbon fuel poses a serious environmental threat to the bodies of water where these types of surface vessels and generators are deployed.
One problem associated with present underwater electricity storage systems is the limited capabilities of the present electricity storage designs. Electricity generated by underwater turbines is generally trickled to a battery which can take a significant amount of time to recharge, thereby limiting the capabilities of the system depending upon such a system. If the battery is uncharged, then the vehicle or structure is incapable of functionally operating until the battery is recharged. In addition, if the batteries are to be exchanged for charged batteries, then the autonomous underwater vehicle must surface so that the batteries can be exchanged. Whether the batteries are to be exchanged for charged batteries or recharged from a charging unit, the vehicle must resurface to be serviced accordingly. An underwater system that depends solely on this slow trickle charge and discharge of a battery to supply dynamic electricity demands severely limits the systems found in the prior art.
It would be beneficial and advantageous to have an underwater electricity generation and storage system that was capable of meeting the dynamic demand of underwater electricity requirements, whether they be by a autonomous underwater vehicle, remotely operated vehicle, stationary underwater structure or other underwater apparatus. Further, it would be beneficial and advantageous to have autonomous underwater vehicles, remotely operated vehicles and stationary underwater structures that are capable of efficiently powering themselves under the water for extended periods of time.
The above and other problems are solved and an advance in the art is made by the underwater vehicle that incorporates a submersible electricity generation and storage system. The underwater vehicle uses a pressurizable waterproof enclosure that contains a novel combination of: electricity generation devices, flywheel power sources, energy collection control circuitry and power distribution control circuitry. The instant application combines these elements to generate and store electricity underwater or at the surface of the water to meet the dynamic electrical requirements of autonomous underwater vehicles, remotely operated vehicles and stationary underwater structures.
Electricity generated by the electricity generating devices is transferred to the energy collection control circuitry. The electricity generating devices are connected to or enclosed within the waterproof enclosure of the system. Electricity transferred to the energy collection control circuitry is then transferred to a flywheel power source. The electricity transferred to a flywheel power source spins up the flywheel power source. Once spun-up, the flywheel power source is a sustained and prolonged supply of electricity to the system""s underwater devices. The flywheel power source is capable of being instantly spun-up, thereby eliminating the time-consuming and non-productive activities associated with recharging and replacing batteries. The present submersible electricity generation and storage system is capable of electrically powering an autonomous underwater vehicle, remotely operated vehicle or stationary underwater structure for extended periods of time.
Another problem solved by the present submersible electricity generation and storage system is that an autonomous underwater vehicle, remotely operated vehicle or stationary underwater structure can be instantly recharged by another autonomous underwater vehicle, remotely operated vehicle or stationary underwater structure. The flywheel power source is charged by the onboard electricity generating device part of the system. Further, the flywheel power source is designed to be charged instantly by another autonomous underwater vehicle, remotely operated vehicle or stationary underwater structure. In a preferred embodiment of the present invention, the submersible electricity generating and storage system on board an autonomous underwater vehicle transfers electricity instantly to one another autonomous underwater vehicle underwater or at the water surface, thereby eliminating the need of crews and equipment to service and recharge the autonomous underwater vehicles. The flywheel power source of one autonomous underwater vehicle, remotely operated vehicle or stationary underwater structure transfers electricity to an electrical apparatus onboard the other autonomous underwater vehicle, remotely operated vehicle or stationary underwater structure.
The submersible electricity generating and storage system can be sized or designed according to the use and electricity requirements of the structure or vehicle. Stationary underwater structures can have system sizes and designs that are commensurate with their electricity requirements. This can include larger rotor turbines and a great number of flywheel power sources. Conversely, autonomous underwater vehicles and remotely operated vehicles which are generally smaller and mobile, can have systems that are appropriately designed to fit within their waterproof bodies.